Cooked fluid?

[sam55]

Just wanted to confirm, if the brake pedal starts to soften and head to the floor, and the discs and pads aren't showing signs of overheating, would this mean the brake fluid has most likely boiled?

 

[Gandi69]

Or you've got a leak/air in the system.

 

[Steven103]

Unless you've got serious pads & s***e fluid it'd be very odd for brake fluid to boil before the pads glaze over. Your description does however match up with pretty much all other descriptions of boilding brake fluid.

Are we talking road or track (I assume track naturally, but you never know) You get similar "sponge pedal" symptoms for example if you just haven't used the brakes particularly hard for a while, e.g. motorway driving. Pads also get knocked on/off of discs by violent bumps (kerbs if we're talking track, wouldn't suprise me if a pothole could do the same) which causes more brake pedal travel to occur the before anything happens the next time you hit the brakes.

Bled the brakes/had fluid changed recently?

 

[sam55]

Cheers for the replies, I'm doing a trackway end of the month and so wanted to test out my new ferodo/brembo hc front set up after bedding them in, took the car to an empty lane and did several hard stops and after like 5 the pedal softened up and headed to the floor. I thought I'd cooked the pads but on inspection they were obvs hot but showed no sign/smell of overheating. Recently re bled the brakes with standard dot 4 so wondered if that would be the explanation.

Before they cooked, the brakes were awesome!